Example embodiments relate to a memory device, a memory system, and a mapping information recovering method.
A flash memory is a type of Electrically Erasable Programmable Read Only Memory (EEPROM) and may be used to replace a Hard Disk Drive (HDD). As compared with a conventional HDD, the flash memory provides more rapid access performance, and its size and power consumption are smaller. Further, since flash memory may be more robust against external impact, it is widely used as a storage device for portable apparatuses.
Storage devices with flash memories, for example flash memory cards, cellular phones, Solid State Drives (SSDs), and the like store mapping information between logical addresses and flash physical addresses. Such mapping information may be generated when a write request is issued with respect to a flash memory. It is possible to store mapping information in a flash memory whenever the mapping information is changed. This may degrade the performance of a storage/memory/computing system including the flash memory. In some systems, the mapping information may be retained in RAM, and the mapping information stored in the RAM may be provided to the flash memory periodically. In this case, no mapping information might be stored in the flash memory at sudden power-off.
The write performance of a storage device may vary according to frequency with which mapping information is stored in a flash memory. Further, a time taken to recover final mapping information before power-off may vary depending on the algorithm used for managing mapping information. This recovery time may be part of an initialization time of a storage device, which may be a factor used to determine a system booting time.